Tom et al,
Yes, CW is keyed on DTR. You need an interface circuit to interface
between your COM port and your radio. A simple transistor interface
for WriteLog can be found at www.aa5au.com/rttyinterface.html. You
can also use an opto-isolator circuit if you want total electrical separation
between COM port and radio.
The interface takes the +12 to -12 vdc highs and lows from the RS-232
port and converts them to open or ground to key CW on your radio.
You can key CW, PTT and FSK (for RTTY) on the same port as well.
73, Don AA5AU
----- Original Message -----
From: "Tom Sessions" <k4rv@mindspring.com>
To: <writelog@contesting.com>
Sent: Friday, July 12, 2002 4:39 PM
Subject: [WriteLog] cw keying, com port
> When configured for "PC Generates" CW on a COMM port, WriteLog sends CW on
> the DTR line of the COMM port.
>
> The above was taken from the help section of Writelog. Would someone
> please further clarify it for me? I measure -5.5 VDC between pin 4(DTR) and
> pin 5(GND) of my selected DB9 com port with no keying going on.
> Does the help explanation mean that WriteLog will key dits and dahs at 0
> VDC with -5.5 VDC in between? Does it mean WriteLog will key dits and dahs
> at +5.5 VDC with -5.5 VDC in between? Or are there some inverse or other
> key up/ keydown voltages?
>
> In essence, what I am asking is what is the DTR pin voltage for "key
> down", and what is the same DTR pin voltage for "key up" ?
>
> Thanks
> Tom K4RV
>
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